Capacitor constructions comprising a nitrogen-containing layer over a rugged polysilicon layer

ABSTRACT

The invention encompasses a method of forming a dielectric material. A nitrogen-comprising layer is formed on at least some of the surface of a rugged polysilicon substrate to form a first portion of a dielectric material. After the nitrogen-comprising layer is formed, at least some of the substrate is subjected to dry oxidation with one or both of NO and N 2 O to form a second portion of the dielectric material. The invention also encompasses a method of forming a capacitor. A layer of rugged silicon is formed over a substrate, and a nitrogen-comprising layer is formed on the layer of rugged silicon. Some of the rugged silicon is exposed through the nitrogen-comprising layer. After the nitrogen-comprising layer is formed, at least some of the exposed rugged silicon is subjected to dry oxidation conditions with one or both of NO and N 2 O. Subsequently, a conductive material layer is formed over the nitrogen-comprising layer. Additionally, the invention encompasses a capacitor structure. The structure includes a first capacitor electrode comprising a rugged polysilicon layer, a nitrogen-comprising layer on the rugged polysilicon layer, and a second capacitor electrode. The nitrogen-comprising layer is between the first and second capacitor electrodes.

TECHNICAL FIELD

[0001] The invention pertains to methods of forming dielectricmaterials, and methods of forming capacitors. The invention alsopertains to capacitor constructions.

BACKGROUND OF THE INVENTION

[0002] It is frequently desired to form dielectric materials duringsemiconductor device fabrication. For instance, capacitor constructionscomprise dielectric material separating a pair of capacitor electrodes.Suitable dielectric materials for capacitor constructions includesilicon dioxide and silicon nitride, with an exemplary dielectricmaterial comprising a stack of silicon nitride between a pair of silicondioxide layers.

[0003] An advantage of utilizing silicon nitride in capacitorconstructions is that it has a higher dielectric constant than silicondioxide. However, a difficulty in utilizing silicon nitride can occur inattempting to get a uniform coating of silicon nitride over a capacitorelectrode. For instance, a capacitor electrode can compriseconductively-doped rugged silicon (for example, conductively-dopedhemispherical grain polysilicon). Such rugged silicon has a roughsurface texture, and is utilized because the rough surface textureenables more conductive surface area to be provided over a particularfootprint than would be provided with a smooth-surfaced structure. Adifficulty can occur in attempting to form silicon nitride over theroughened surface structure of rugged silicon. Specifically, siliconnitride is typically provided by chemical-vapor deposition (such as, forexample, low pressure chemical vapor deposition utilizing silane andammonia as precursors), and the nitride deposits non-conformally on theroughed surface of the rugged silicon. Accordingly, if the nitride isprovided as a thin layer (less than 100 Å thick), there can be pinholesextending into the nitride, and even extending through the nitride toexpose portions of the underlying rugged silicon surface.

[0004] Among the methods which have been developed to compensate for thepinhole problems are methods in which silicon dioxide is formed over thelayer of silicon nitride to either fill the pinholes or at least coverthe pinholes with a dielectric material. The silicon dioxide can beformed by either chemical vapor deposition, or by oxidation of thesilicon nitride surface.

[0005] Another method for compensating for pinhole problems is to formsilicon dioxide over the rugged polysilicon prior to formation of thesilicon nitride. Accordingly, a dielectric material will be beneath thesilicon nitride, and any pinholes extending through the silicon nitridecan be prevented from exposing the underlying conductive substrate bythe intervening layer of silicon dioxide.

[0006] In typical prior art processing, both of the above-discussedsilicon dioxide methodologies are utilized. In other words, a layer ofsilicon dioxide is formed before forming the layer of silicon nitride,and a second layer of silicon dioxide is formed after forming the layerof silicon nitride.

[0007] It would be desirable to develop methods wherein some or all ofthe above-discussed difficulties associated with formation of siliconnitride could be eliminated, and particularly it would be desirable todevelop methods wherein one or both of the above-discussed layers ofsilicon dioxide could be eliminated from capacitor constructions.

SUMMARY OF THE INVENTION

[0008] In one aspect, the invention encompasses a method of forming adielectric material. A nitrogen-comprising layer is formed on at leastsome of the surface of a rugged polysilicon substrate to form a firstportion of a dielectric material. After the nitrogen-comprising layer isformed, at least some of the substrate is subjected to dry oxidationwith one or both of NO and N₂O to form a second portion of thedielectric material.

[0009] In another aspect, the invention encompasses a method of forminga capacitor. A layer of rugged silicon is formed over a substrate, and anitrogen-comprising layer is formed on the layer of rugged silicon. Someof the rugged silicon is exposed through the nitrogen-comprising layer.After the nitrogen-comprising layer is formed, at least some of theexposed rugged silicon is subjected to dry oxidation conditions with oneor both of NO and N₂O. Subsequently, a conductive material layer isformed over the nitrogen-comprising layer.

[0010] In yet another aspect, the invention encompasses a capacitorstructure. The structure includes a first capacitor electrode comprisinga rugged polysilicon layer, a nitrogen-comprising layer on the ruggedpolysilicon layer, and a second capacitor electrode. Thenitrogen-comprising layer is between the first and second capacitorelectrodes.

BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Preferred embodiments of the invention are described below withreference to the following accompanying drawings.

[0012]FIG. 1 is a diagrammatic, fragmentary, cross-sectional view of asemiconductor wafer fragment at a preliminary processing step of amethod of the present invention.

[0013]FIG. 2 is an exploded view of a portion of the FIG. 1 waferfragment.

[0014]FIG. 3 is a view of the FIG. 2 portion shown at a processing stepsubsequent to that of FIG. 2.

[0015]FIG. 4 is a view of the FIG. 2 portion shown at a processing stepsubsequent to that of FIG. 3.

[0016]FIG. 5 is a view of the FIG. 1 wafer fragment shown at aprocessing step corresponding to that of FIG. 4.

[0017]FIG. 6 is a view of the FIG. 1 wafer fragment shown at aprocessing step subsequent to that of FIG. 5.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] This disclosure of the invention is submitted in furtherance ofthe constitutional purposes of the U.S. Patent Laws “to promote theprogress of science and useful arts” (Article 1, Section 8).

[0019] An exemplary method of the present invention is described withreference to FIGS. 1-6. Referring initially to FIG. 1, a semiconductorwafer fragment 10 is illustrated at a preliminary processing step of amethod of the present invention. Wafer fragment 10 comprises a substrate12 having an insulative material 14 provided thereover. Substrate 12 cancomprise, for example, monocrystalline silicon lightly doped with ap-type background dopant. To aid in interpretation of the claims thatfollow, the terms “semiconductive substrate” and “semiconductorsubstrate” are defined to mean any construction comprisingsemiconductive material, including, but not limited to, bulksemiconductive materials such as a semiconductive wafer (either alone orin assemblies comprising other materials thereon), and semiconductivematerial layers (either alone or in assemblies comprising othermaterials). The term “substrate” refers to any supporting structure,including, but not limited to, the semiconductive substrates describedabove.

[0020] Insulative material 14 can comprise, for example,borophosphosilicate glass (BPSG).

[0021] A conductively doped diffusion region 16 is provided withinsubstrate 12, and defines an electrical node. Diffusion region 16 can bedoped with either n-type or p-type conductivity-enhancing dopant. Waferfragment 10 further comprises a transistor structure 50 comprising agate oxide 52, a conductive material 54 and an insulative cap 56.Conductive material 54 can comprise, for example, one or both ofconductively doped silicon and metal silicide, and in typicalconfigurations comprises a layer of conductively doped polysiliconbeneath a layer of metal silicide. Layers 52, 54 and 56 comprisesidewalls, and spacers 58 are formed along such sidewalls. Spacers 58can comprise, for example, anisotropically etched silicon nitride. Inthe shown embodiment, electrical node 16 is a source/drain region oftransistor structure 50, and another source/drain region 60 is showngatedly connected with electrical node 60. Source/drain regions 16 and60 comprise heavily-doped regions, (i.e., regions doped to at least aconcentration of 1×10¹⁹ atoms/cm³ with conductivity-enhancing dopant).Lightly doped diffusion regions 62 extend beneath sidewall spacers 58,with lightly doped diffusion regions 62 being less heavily doped thansource/drain regions 16 and 60. Transistor structure 50 can be formed byconventional methods.

[0022] An opening 18 extends through insulative material 14 and toelectrical node 16. A first capacitor electrode 20 extends withinopening 18, and comprises conductively-doped rugged silicon, such as,for example, conductively-doped hemispherical grain polysilicon.Conductive material 20 can be formed by conventional methods, and isshown patterned into a structure which extends over a top surface ofinsulative material 14, and within opening 18 to contact electrical node16. Material 20 comprises a roughened outer surface 22.

[0023] A nitrogen-comprising layer 24 is formed over roughened surface22. Nitrogen-comprising layer 24 can comprise, for example, siliconnitride, and can be formed by, for example, chemical vapor deposition.For instance, nitrogen-comprising layer 24 can be formed utilizing lowpressure chemical vapor deposition with silane and ammonia asprecursors. Layer 24 is preferably formed to a thickness of less thanabout 60 Å, and can be formed to an exemplary thickness of from about 40Å to about 60 Å. Due to problems discussed above in the “Background”section of this disclosure, layer 24 does not have a uniform thicknessacross roughened surface 22. Accordingly, layer 24 has some regionswhich are relatively thin, and other regions which are relatively thick.Further, layer 24 can have openings extending therethrough to exposesome of the underlying conductive material of first electrode 22. Suchis illustrated in FIG. 2, which shows an exploded view of a portion ofthe FIG. 1 structure. Specifically, FIG. 2 shows nitrogen-comprisinglayer 24 covering only portions of conductive material 20, and leavingother portions (labeled as portions 26 in FIG. 2) exposed throughopenings in nitrogen-comprising layer 24. It is noted that even thoughthe exposed portions 26 are shown resulting from non-conformal coatingof nitrogen-comprising layer 24 over corners, exposed portions ofconductive material 20 can also result from pinholes (not shown)extending through layer 24.

[0024] Although nitrogen-comprising layer 24 is shown formed onconductive material 20, it is to be understood that the inventionencompasses other embodiments (not shown) wherein a dielectric materialis formed over conductive material 20 prior to formation ofnitrogen-comprising layer 24. For instance, a layer of silicon dioxidecould be formed over conductive material 20 prior to provision ofnitrogen-comprising layer 24. Such layer of silicon dioxide can beformed by chemical vapor deposition, or by oxidation. In someembodiments, the layer of silicon dioxide can be a “native” layer,formed by exposure of a silicon-containing surface to air. In the shownembodiment, there is no native oxide over surface 22 when nitride layer24 is deposited. Such can be accomplished by either avoiding exposure ofsurface 22 to conditions which form native oxide, or by removing nativeoxide (by, for example, a hydrofluoric acid dip) prior to formation oflayer 24. It can be advantageous to avoid having a silicon dioxide layerbetween nitride layer 24 and surface 22, as silicon dioxide has a lowerdielectric constant than silicon nitride.

[0025] In accordance with methodology of the present invention, exposedregions 26 are treated by dry oxidation with one or both of NO and N₂Oto form a dielectric material from exposed portions 26. FIG. 3 shows theFIG. 2 portion of wafer fragment 10 after treatment with one or both ofNO and N₂O, whereupon dielectric caps 28 have been formed overpreviously exposed portions 26 (FIG. 2) of surface 22. The dielectricmaterial of caps 28 comprises one or both of silicon dioxide and siliconnitride. Specifically, regardless of whether NO or N₂O is utilized fordry oxidation of silicon-comprising surface 22, there is potential toform silicon nitride from the nitrogen component, as well as potentialto form silicon dioxide from the oxygen component. It can beadvantageous to form silicon nitride, as such has a higher dielectricconstant than silicon dioxide. However, regardless of whether siliconnitride, silicon dioxide, or both is formed, exposed portions of surface22 will be protected with a dielectric material cap.

[0026] Advantages of utilizing NO and/or N₂O dry oxidation overconventional O₂ dry and wet oxidation (O₂ and water) can include (1) theNO and/or N₂O treatment can convert an exposed portion of the surface 22into oxynitride which has a higher dielectric constant than siliconoxide; (2) the reaction of NO and N₂O with the exposed portion of thesurface 22 is self-limited, which means that the thickness of theoxynitride or oxide dielectric layer can be very thin and uniform; and(3) the oxynitride or oxide layer formed by NO and/or N₂O oxidation canbe denser than oxide formed by O₂ or wet oxidation.

[0027] It can be desirable for the thickness of the oxynitride or oxidedielectric layer to be thin and uniform because an oxynitride or oxideformed by methodology of the present invention can have a lowerdielectric constant and lower leakage that a nitrogen-comprising layer.A combination of a relatively thick nitrogen-comprising layer 24 with athin oxynitride layer can give better electric performance of an overalldielectric material than would a dielectric material having a thickeroxynitride layer. It is difficult to form an optimum structure onconductive material 20 using O₂ dry oxidation or wet oxidation.

[0028] It can be desirable to have a dense oxide or oxynitride layer assuch can alleviate severe oxidation of conductive material 20 in asubsequent wet oxidation process. Severe oxidation of material 20 cancreate a thick oxide dielectric layer and reduce capacitance of acapacitor incorporating the dielectric layer due to the lower dielectricconstant of the oxide relative to the nitride.

[0029] It is noted that even though the invention is described withreference to a method of treating “exposed” portions of a conductivematerial, it is to be understood that the invention can also be utilizedto treat portions of a conductive material which are beneath a very thinportion of nitride layer 24, (with an exemplary very thin portion ofnitride layer 24 being a portion which is less than or equal to 5 Åthick), rather than being actually exposed through layer 24.

[0030] Dielectric caps 28 can be formed to a thickness of, for example,from about 10 Å to about 30 Å, with an exemplary thickness being about20 Å. Exemplary dry oxidation conditions comprise a flow rate of fromabout 0.01 SLM to about 15 SLM of one or both of NO and N₂O, atemperature of from about 700° C. to about 850° C., a pressure withinthe reaction chamber of from about 10 mTorr to about 760 Torr, and atreatment time of from about 5 minutes to about 120 minutes. The NOand/or N₂O can be the only nitrogen-containing materials flowed into thereaction chamber. Alternatively, a nitrogen-comprising carrier gas, suchas, for example, N₂, can also be flowed into the reaction chamber.Another suitable carrier gas is Ar. An exemplary flow rate of a carriergas is from about 0.1 SLM to about 20 SLM.

[0031] Referring to FIG. 4, a layer 30 of silicon dioxide is formed overnitrogen-comprising material 24. Layer 30 can comprise, consistessentially of, or consist of silicon dioxide. Layer 30 can be formedby, for example, wet oxidation of surfaces of nitrogen-comprisingmaterial 24 and dielectric caps 28. For instance, if layer 24 comprisessilicon nitride, and caps 28 comprise one or both of silicon dioxide andsilicon nitride, layer 30 can be formed by oxidation of thesilicon-comprising surfaces. Such oxidation can comprise wet oxidationutilizing, for 2 example, O₂ and water at a temperature of from about700° C. to about 850° C. Formation of layer 30 can also comprisechemical vapor deposition of silicon dioxide utilizing, for example,tetraethyl orthosilicate (TeOS) as an oxide precursor. The chemicalvapor deposition of silicon dioxide can be done alternatively to, or inaddition to, wet oxidation. An advantage of utilizing wet oxidation isthat such can form Si—O bonds from dangling Si bonds beneath caps 28.More specifically, the dry NO and/or N₂O oxidation described withreference to FIGS. 2 and 3 typically will form Si—N or Si—O bonds fromdangling Si bonds near a surface of conductive material 20. The wetoxidation can penetrate deeper than the dry oxidation, and accordinglycan form Si—O bonds from dangling bonds that were too deep to beaffected by the dry oxidation conditions.

[0032] Referring to FIG. 5, wafer fragment 10 is shown in a viewcorresponding to that of FIG. 1, and in a processing step correspondingto that of FIG. 4. Accordingly, wafer fragment 10 comprisesnitrogen-comprising layer 24 and silicon dioxide layer 30 formed overfirst capacitor electrode 20.

[0033] Referring to FIG. 6, a second capacitor electrode 32 is formedover silicon dioxide layer 30. Second capacitor electrode 32 comprises aconductive material, and can, for example, comprise conductively dopedsilicon, such as, for example, conductively doped polysilicon orconductively doped amorphous silicon. Alternatively, second capacitorelectrode 32 can comprise metal, such as, for example, a metal alloy ormetal silicide. Second electrode 32, first electrode 20, and dielectriclayers 24 and 30 together define a capacitor construction 40.

[0034] It is to be understood that the processing described above withreference to FIGS. 1-6 is exemplary processing, and that the inventionencompasses other embodiments besides those specifically illustrated.For instance, although a silicon dioxide layer 30 is shown being formedover nitride-comprising layer 24, the invention encompasses embodimentswherein layer 30 is not formed, and instead second electrode 32 isformed on nitrogen-comprising layer 24 after the dry oxidation. Also,although the invention is described with reference to formation of adielectric layer in a capacitor construction, it is to be understoodthat the invention encompasses formation of dielectric layers in otherconstructions besides capacitor constructions.

[0035] In particular processing, the only layers between first electrode20 and second electrode 32 are nitrogen-comprising layer 24 and silicondioxide layer 30. Also, the invention encompasses constructions whereina first capacitor electrode 20 comprises rugged polysilicon, and whereinsuch electrode is utilized in a capacitor construction that comprisesonly one or both of silicon nitride comprising layer 24 and silicondioxide layer 30 between the first capacitor electrode and a secondcapacitor electrode.

[0036] The capacitor construction of FIG. 6 comprises a junction betweenfirst electrode 20 and electrical node 16. Measurements of current flowacross such junction can be compared to measurements of current flowacross a similar junction formed in a conventional capacitorconstruction (i.e., a capacitor construction comprising a dielectricmaterial with a layer of silicon nitride formed between a pair of layersof silicon dioxide), to determine if methodology of the presentinvention adversely affects device performance. Such comparisons havebeen conducted, and show that devices formed in accordance with themethodology of the present invention can have performancecharacteristics comparable to, or exceeding those of conventionaldevices. Accordingly, the formation of silicon nitride layer 30 directlyon a silicon-comprising first electrode 20 does not create stresses thatdestroy device performance.

[0037] In alternative processing (not shown), a bit line can beelectrically connected with source/drain region 60. Thus, capacitor 40and transistor structure 50 can together define a DRAM cell.

[0038] In compliance with the statute, the invention has been describedin language more or less specific as to structural and methodicalfeatures. It is to be understood, however, that the invention is notlimited to the specific features shown and described, since the meansherein disclosed comprise preferred forms of putting the invention intoeffect. The invention is, therefore, claimed in any of its forms ormodifications within the proper scope of the appended claimsappropriately interpreted in accordance with the doctrine ofequivalents.

1. A method of forming a dielectric material, comprising: forming anitrogen-comprising layer on at least some of a surface of a ruggedpolysilicon substrate to form a first portion of a dielectric material;and after forming the nitrogen-comprising layer, subjecting at leastsome of the substrate to dry oxidation with one or both of NO and N₂O toform a second portion of the dielectric material.
 2. The method of claim1 wherein the one or both of NO and N₂O comprises both NO and N₂O. 3.The method of claim 1 wherein the one or both of NO and N₂O comprises NOand not N₂O.
 4. The method of claim 1 wherein the one or both of NO andN₂O comprises N₂O and not NO.
 5. The method of claim 1 wherein thenitrogen-comprising layer is over only some of the rugged polysilicon;wherein the rugged polysilicon comprises portions which are exposedthrough the nitrogen-comprising layer; and wherein the dry oxidationforms one or both of silicon dioxide and silicon nitride from thepolysilicon of the exposed portions.
 6. The method of claim 1 furthercomprising, after subjecting at least some of the substrate to the dryoxidation conditions, subjecting the substrate to wet oxidationconditions.
 7. The method of claim 1 further comprising, aftersubjecting at least some of the substrate to the dry oxidationconditions, forming a layer comprising silicon dioxide over thenitrogen-comprising layer.
 8. A method of forming a dielectric material,comprising: forming a nitrogen-comprising layer over a semiconductorsubstrate to form a first assembly; subjecting the first assembly to dryoxidation conditions with an oxidant comprising one or both of NO andN₂O; and after subjecting the first assembly to the dry oxidationconditions, subjecting the first assembly to wet oxidation conditions.9. The method of claim 8 wherein the one or both of NO and N₂O comprisesboth NO and N₂O.
 10. The method of claim 8 wherein the one or both of NOand N₂O comprises NO and not N₂O.
 11. The method of claim 8 wherein theone or both of NO and N₂O comprises N₂O and not NO.
 12. The method ofclaim 8 wherein the forming the nitrogen-comprising layer compriseschemical vapor deposition.
 13. The method of claim 8 wherein thenitrogen-comprising layer is formed to a thickness of less than or equalto 60 Å.
 14. The method of claim 8 wherein the nitrogen-comprising layeris formed to a thickness of from about 40 Å to about 60 Å.
 15. Themethod of claim 8 wherein the semiconductor substrate comprises ruggedsilicon, and wherein the nitrogen-comprising layer is formed on therugged silicon.
 16. The method of claim 8 wherein the semiconductorsubstrate comprises silicon, and wherein the wet oxidizing conditionsform silicon dioxide.
 17. A method of forming a capacitor, comprising:forming a layer of rugged silicon over a substrate; forming anitrogen-comprising layer on at least some of a surface of the ruggedsilicon to form a first portion of a dielectric material; and afterforming the nitrogen-comprising layer, utilizing dry oxidation with oneor both of NO and N₂O to form a second portion of the dielectricmaterial; and forming a conductive material layer over thenitrogen-comprising layer; the conductive layer, rugged silicon, anddielectric material together defining a capacitor construction.
 18. Themethod of claim 17 wherein the one or both of NO and N₂O comprises bothNO and N₂O.
 19. The method of claim 17 wherein the one or both of NO andN₂O comprises NO and not N₂O.
 20. The method of claim 17 wherein the oneor both of NO and N₂O comprises N₂O and not NO.
 21. The method of claim17 wherein the nitrogen-comprising layer is formed to a thickness ofless than or equal to 60 Å.
 22. The method of claim 17 wherein thenitrogen-comprising layer is formed to a thickness of from about 40 Å toabout 60 Å.
 23. The method of claim 17 wherein the nitrogen-comprisinglayer is over only some of the rugged silicon; wherein the ruggedsilicon comprises portions which are exposed through thenitrogen-comprising layer; and wherein the dry oxidation forms one orboth of silicon dioxide and silicon nitride from the silicon of theexposed portions.
 24. The method of claim 17 further comprising, afterutilizing the dry oxidation conditions, forming a layer comprisingsilicon dioxide over the nitrogen-comprising layer, and forming theconductive material over the layer comprising silicon dioxide.
 25. Themethod of claim 24 wherein the layer comprising silicon dioxide is alayer consisting of silicon dioxide.
 26. The method of claim 25 whereinthe conductive material is formed on the layer of silicon dioxide. 27.The method of claim 17 further comprising, after utilizing the dryoxidation conditions; forming a layer of silicon dioxide over thenitrogen-comprising layer by utilizing wet oxidation conditions.
 28. Amethod of forming a capacitor, comprising: forming a layer of ruggedsilicon over a substrate; forming a nitrogen-comprising layer on thelayer of rugged silicon, some of the rugged silicon being exposedthrough the nitrogen-comprising layer; after forming thenitrogen-comprising layer, subjecting at least some of the exposedrugged silicon to dry oxidation conditions with one or both of NO andN₂O; and forming a conductive material layer over thenitrogen-comprising layer.
 29. The method of claim 28 wherein the one orboth of NO and N₂O comprises both NO and N₂O.
 30. The method of claim 28wherein the one or both of NO and N₂O comprises NO and not N₂O.
 31. Themethod of claim 28 wherein the one or both of NO and N₂O comprises N₂Oand not NO.
 32. The method of claim 28 wherein the nitrogen-comprisinglayer is formed to a thickness of less than or equal to 60 Å.
 33. Themethod of claim 28 wherein the nitrogen-comprising layer is formed to athickness of from about 40 Å to about 60 Å.
 34. The method of claim 28further comprising, after subjecting at least some of the exposed ruggedsilicon to the dry oxidation conditions, forming a layer of silicondioxide over the nitrogen-comprising layer, and forming the conductivematerial over the layer of silicon dioxide.
 35. The method of claim 34wherein the conductive material is formed on the layer of silicondioxide.
 36. The method of claim 28 further comprising, after subjectingthe at least some of the exposed rugged silicon to the dry oxidationconditions, utilizing wet oxidation conditions to form a layer ofsilicon dioxide over the nitrogen-comprising layer.
 37. The method ofclaim 28 wherein the conductive material comprises conductively-dopedsilicon.
 38. A capacitor structure, comprising: a first capacitorelectrode comprising a rugged polysilicon layer; a nitrogen-comprisinglayer on the rugged polysilicon layer; and a second capacitor electrode;the nitrogen-comprising layer being between the first and secondcapacitor electrodes.
 39. The capacitor structure of claim 38 whereinthe nitrogen-comprising layer has a thickness of less than or equal to60Å.
 40. The capacitor structure of claim 38 wherein thenitrogen-comprising layer has a thickness of from about 40 Å to about 60Å.
 41. The capacitor structure of claim 38 further comprising a layerconsisting essentially of silicon dioxide on the nitrogen-comprisinglayer; the layer consisting essentially of silicon dioxide being betweenthe nitrogen-comprising layer and the second capacitor electrode. 42.The capacitor structure of claim 41 wherein the only dielectricmaterials between the first and second capacitor electrodes are thenitrogen-comprising layer and the layer consisting essentially ofsilicon dioxide.
 43. The capacitor structure of claim 38 furthercomprising a layer consisting of silicon dioxide on thenitrogen-comprising layer, the layer consisting of silicon dioxide beingbetween the nitrogen-comprising layer and the second capacitorelectrode.
 44. The capacitor structure of claim 43 wherein the onlydielectric materials between the first and second capacitor electrodesare the nitrogen-comprising layer and the layer consisting of silicondioxide.